Regenerative pumps are the subject of increased interest in industry as these pumps are low cost, low specific speed, compact and able to deliver high heads with stable performance characteristics. The complex flow-field within the pump represents a considerable challenge to detailed mathematical modelling. This paper outlines the use of a commercial CFD code to simulate the flow-field within the regenerative pump and compare the CFD results with new experimental data. A novel rapid manufacturing process is used to consider the effect of impeller geometry changes on the pump efficiency. The CFD results demonstrate that it is possible to represent the helical flow field for the pump which has only been witnessed in experimental flow visualisation until now. The CFD performance results also demonstrate reasonable agreement with the experimental tests. The ability to use CFD modelling in conjunction with rapid manufacturing techniques has meant that more complex impeller geometry configurations can now be assessed with better understanding of the flow-field and resulting efficiency
This paper presents a novel approach to repair modeling using a time domain Auto-Regressive model to represent meteo-ocean site conditions. The short term hourly correlations, medium term access windows of periods up to days and the annual distribution of site data are captured. In addition, seasonality is included. Correlation observed between wind and wave site can be incorporated if simultaneous data exists. Using this approach a time series for both significant wave height and mean wind speed is described. This allows MTTR to be implemented within the reliability simulation as a variable process, dependent on significant wave height. This approach automatically captures site characteristics including seasonality and allows for complex analysis using time dependent constraints such as working patterns to be implemented. A simple cost model for lost revenue determined by the concurrent simulated wind speed is also presented. A preliminary investigation of the influence of component reliability and access thresholds at various existing sites on availability is presented demonstrating the ability of the modeling approach to offer new insights into offshore wind turbine operation and maintenance.
A novel architecture and system for the provision of Reliability Centred Maintenance (RCM) for offshore wind power generation is presented. The architecture was developed by conducting a bottom-up analysis of the data required to support RCM within this specific industry, combined with a top-down analysis of the required maintenance functionality. The architecture and system consists of three integrated modules for intelligent condition monitoring, reliability and maintenance modelling, and maintenance scheduling that provide a scalable solution for performing dynamic, efficient and cost-effective preventative maintenance management within this extremely demanding renewable energy generation sector. The system demonstrates for the first time the integration of state-of-the-art advanced mathematical techniques: Random Forests, dynamic Bayesian networks and memetic algorithms in the development of an intelligent autonomous solution. The results from the application of the intelligent integrated system illustrated the automated detection of faults within a wind farm consisting of over 100 turbines, the modelling and updating of the turbines' survivability and creation of a hierarchy of maintenance actions, and the optimizing of the maintenance schedule with a view to maximizing the availability and revenue generation of the turbines.
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Regenerative pumps are low cost, compact, able to deliver high heads at low flow rates. Furthermore with stable performance characteristics they can operate with very small NPSH. The complexity of the flow field is a serious challenge for any kind of mathematical modelling. This paper compares an analytical and numerical technique of resolving the performance for a new regenerative pump design. The performance characteristics computed by a CFD approach and a new one-dimensional model are compared and matched to experimental test results. The approaches of both modelling techniques are assessed as potential design tools. The approaches are shown to not only successfully resolve the complex flow field within the pump; the CFD is also capable of resolving local flow properties to conduct further refinements. The flow field is represented by the CFD as it has never been before. A new design process is suggested. The new regenerative pump design is considered with a comparable duty centrifugal pump, proving that for many high head low flow rate applications the regenerative pump is a better choice
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